CHAPTER 2

41

"Future of Earth -- Now or never"

-- Sandra Postel

METALLURGICAL MATERIALS

'I STEEL PLANT SLAG

f FOUNDRY SLAG tziNC SMELTER SLAG :MILL SCALES ZFERROMANGANESE ~LLOY

THEIR GENESIS,AVAILABILITIES, REDUCTION BEHAVIOURS

2.1 STEEL PLANT SLAG GENESIS AND AVAILABILITY

Slag is the name applied to the fused product

formed by the action of the flux upon the gangue of an

ore or fuel, or upon the oxidised impurities of the

metal. The slag results from the nuetralization of

materials of acidic and basic nature, hence corresponds

roughly to salts formed in aqueous solution during

chemical reactions at ordinary temperature (1). On

account of their fusibility, chemical activity,

dissolving power and low density, slags furnish the

means by which impurities are separated from the

metal, and removed from the furnace in iron and steel

making processes.

In the blast furnace, solid charge materials

(iron ore, coke and limestone), are charged in the

vertical shaft of the furnace at the top and hot air

blast is blown through tuyeres (Fig 2-1) located at the

bottom. The oxygen from the preheated blast combines

with the carbon of coke, and generates heat and carbon

monoxide. The gas phase containing mainly N2

and CO

ascends upwards through the charge which reacts with

and extracts heat from the gas phase. Eventual] y; the

charge melts, and metal and slag thus produced are

stratified and separated to obtain the metal.

The main chemical reactions are the reduction

of iron oxide and the burning of coke (2).

42

2C + 02 ---7 2CO

2Fe0 + 3CO ---7 3C02 + 4Fe

Fe 2o 3 + 3C ---7 3CO + 2Fe

C0 2 + c -t 2CO

Limestone and Dolomite which are used

charge get calcined as

Caco3 -7 CaO

MgC03~ MgO

+

+

as flux in the

The resulting basic oxides combine with the gangue

oxides to form the slag (Fig 2-1).

Composition of blast furnace slag is rather

complex. Up to thirty different chemical elements occur

in the slags mainly in the form of oxides. The

principal ones include

MgO. Usually present in lesser amounts are :FeO, MnO,

so3 , P2o 5 , Tio2 , v2o 5 and others. Depending on the

value of the so called modulus of basicity,

[ %Ca0 + %Mg0 ) all the blast furnace slags obtained %Si02 + %Al 2o3

at ferrous metallurgy enterprises can be divided· into

three groups, namely acidic, basic and neutral (3).

The chemical compositions of hl ast furnace

slags in Russia have been reported (31 in the fnlln~inJ•

43

Gas -+---

200• Stock line Expulsion of water

600

Sponge Iron formation

1200.

•

Molten metal &. Slag Formation

1500" Combustion

Bell LCone

T hroal --5m---

3 Fe 2o3•CO ~ 2 Fe30~• C02

Fe 3 O~+CO;;!: 3 Fe O•C02

Stack

Cylinder or BellY

-- --- 6.5 m ----

Bosh

FeO+C ::;:!:" Fe+CO

MnO•·C:;:!: Mn+CO

Si0t2C ~ Si+2CO

p2

o5+5C =2P+5CO

MnS+CaO+C

= Mn +CaS+CO

CaO+SI 02 = CaS;OJ

C02 + C = 2 CO

Tuyerts __,..

I Hearth Slag notch ~

~---7.5m----

C +02-:.C02

FIG.-

~ Mrtal Tap Hole

DIAGRAM OF A BLAST FURNACE SHOWING THE

CHEMICAL REACTIONS.

44

45

ranges (%) :

Si02

35.0-39.9; A12o

3 7.0-16.3; CaO 30.4-46.3;

MgO 2.3-14.3; FeO 0.2-0.7; MnO 0.3-2.9;

s 0.5-4.7.

The composition of slags depends upon chemical

composition of raw materials, operation factors and

grades of metals to be produced. The chemical

composition of blast furnace slags, in Indian steel

industries, has been reported to be in the following

ranges Si02 33-42"/.; Al 2o3 10-15"/o; CaO 36-45%; t1g0

3-12%; S 1-3%; FeO 0.3-2%; MnO 0.2-1.5% (4). The

average chemical composition of blast furnace slag of

Bhilai Steel Plant to which the work described is

rel ated1 has been reported as follows Sio2

34-53%;

Al 20 3 22. 38'7o; CaO 34-7 5%; MgO 5. 80%; FeO 0. 81'7o; Mn

0.59%; s 0.74% (4,5).

Indian slags are characterised by comparatively

a high alumina content resulting from the use of more

aluminous iron ore and high ash metallurgical coke (6).

As high alumina content is known to increase viscosity

of melt, dol amite is added to get low viscosity slags

for proper operation of blast furnace. Mn-ore is added

to minimise harmful effects of sulphur and allowing it

to increase Strength and toughness of steel.

Steel melting shops in steel manufacturing

industries form another source for the disch;H[!C of

slags. The production of slags from this source is

about 20 kg/tonne of steel manufactured, compared to

500-600 kg per tonne of hot metal in the case of blast

furnace. The composition of SMS slag has been reported

as follows Si02 10-20%, FeO 8-10%; CaO 30-40%; NgO

3-10%; Al 2o3 4-10% <7).

The total amount of the blast furnace slags

currently turned out by Russian industrial enterprises

exceeds 50-52 million tonnes a year, and comprise the

largest single waste of the metallurgical melting

process (3). About 80% blast furnace slag and 28.5% SMS

slag stand utilized in Russia,Granulated slags (54% of

the total production) and broken slags ( 35/o) are

produced on the largest seal e. In India, the usage of

blast furnace slag is based on the mode of production

of the slag, namely air-cooled variety has application

for use as aggregate for portland cement concrete, for

road construction, as rail road ballast, as roofing

material, as sewage filter media in ceramic-ware

making, as soil conditioner, in slag wool manufacture

and as land-fill material in low lying areas and

embankments. The granulated variety of the slag is used

in· the manufacture of slag based portland cement, slag

bricks, mortars, opaque and transparent glass and as a

land-fill material for worked-out mines, road1vays and

railway embankments. The installed capacity of the

ingot steel envisaged in India by 2000 A.O. is 7'i

46

47

million tonnes. The world steel production figures of

1990 and 1991 were 735.3 and 769.8 million tonnes

respectively (8). Steel productions in India during the

same years were 15.0 and 17.1 million tonnes respectively

(8). The average rate of discharge of slags in India is

615 kg/tonne of steel manufactured (9). The figures

speak of the massive availability of steel plant s1 ags

in India.

2.2 FOUNDRY SLAGS : GENESIS AND AVAILABILITY

A foundry is that in which metals are reduced to

fluid state and poured into moulds of various types.

When the liquid metal has cooled, and the mound has been

removed, the finished pro~uct is called a casting. Nowa­

days, cas tin:; represents an extreme] j important sector

in components used in engineerin6. By mel tin;;, it is

possible to obtain highly complicated shapes for

components which would otherwise be extremely expensive,

or even impossible to produce by machine tools (10).

~1eta1 founding on modern 1 ines for mass production

of industrial castings was started in India in the later

half of 19th century. Today, this section forms the

backbone of the engineering industry, manufcturing a

wide range of various range of castings of various

specifications such as plain carbon, stainless

steel , wear resistant, corrosion resistant

and creep resistant steels. The weight of these

castings may range from few grams to hundred tonnes

single piece, and simple to most intricate ones to meet

the ever increasing technological requirements of the

country and overseas market. Indian railways account

for around 40% of the total demand for steel castings

in the country (11).

48

Steel foundries in India are located at Durg,

Raipur, Agra, Delhi, Ghaziabad, Faridabad, Varanasi,

Kanpur, Luckhnow, Calcutta, Asansol, Burnpur, Dhanbad,

Bokaro, Jamshedpur, Rourkela, Durgapur, Bombay, Nagpur,

Ahmedabad, Baroda, Jhansi, Visakhapatnam, Salem, Madras

and Indore. Today, over three dozen foundries

manufacture about ninty thousand tonnes of alloy steel

castings per year ( 12). In the region of Durg and

Raipur districts of Hadhya Pradesh, five major steel

foundries manufacture over 5000 tonnes of alloy steel

and precision castings over a year. In foundry process,

scrap iron, iron ore, ferromanganese, lime stone,

dolomite, bauxite and coke are fed into an electric arc

furnace in specified ratios to produce molten iron of

desired specifications. The molten metal is then poured

in especially prepared silica moulds to produce

castings of various sizes and uses. The castings are

then taken otit and dipped in water for quenching. About

2% of the total molten iron produced is clischaq~ed in

the form of slag, and scraped out of the f11rnacc

periodical] v.

The sl.ags of the foundries located in

Durg-Raipur region have been reported to have the

following composition (%)

3.1-5.6; Al 2o3 17.5-19.5; Mno 4 4.3-4.5; CaD 13.4-16.5;

MgO 5.8-6.4; Na 2o 0.5-0.8; K2o 0.2-0.3 (13). The slag

has further been reported to be alkaline in nature. The

pH of the 10% slurry in water has been reported to be

in the range of 9.8-10.2. Its solubility at 20°C has

been reported to be between 4.2-4.5 mg (13).

2.3 ZINC SMELTER SLAGS THEIR GENESIS

Sinter and coke are fed into the sh~ft of the

smelter furnace from the top, and the blast air enters

through tuyeres in the lower part of the furnace. Lead

and slag are tapped from the furnace hearth, and

furnace gas and zinc vapour leave the shaft through the

furnace off-take. The overflowing slag from the hearth

is directed into a launder in which it is granulated by

high pressure water jets. The slag is shifted through

perforated buckets from the slag pit to the slag bin at

a rate of 50 tonnes/hour. The slag from the bin is then

discharged into dumpers which transport it to the area

earmarked for the slag storage. The slag could be

described as silicates of Ca,Al ,Fe, Zn etc which form

gl~ss like granules during the granulation process. It

is vitreous and nonporous with a bulk densitv of 2.00

49

tonne/m5 . The main partie] e size ( 78%) is +500 micron.

The typical chemical composition of the slag is as

follows (14) Fe2o3 32.2-40.0, Si02 18.0-22.0, CaO

12.0-16.0, AJ2o

3 7.0-9.0, Zn 4.0-10.0, MgO 2.0-3.5, S

1.0-2.5, Pb 1.0-2.0, Cu 0.1-0.2, As 0.2-0.3.

2.4 MILL SCALES THEIR GENESIS

In the process of rolling, semi-finished

products like ingots, blooms, slabs, billets etc have

to be reheated before these are rolled into finished

products. This reheating process is necessiated by the

logistics or scheduling of the rolling operations

and/or the need to condition the surfaces of the semi­

finished work pieces.

50

Basically, the reheating operation is intended

to raise as uniformly as possible the temperature of

the blooms, slabs or billets etc to the l.evels

appropriate for hot rolling. This operation is carried

out in a reheating furnace. In most reheating furnace

of conventional design, work pieces undergo scaling due

to the oxidation. Although this results in a yield loss

of 1-5%, it is often regarded as desirable in removing

superficial defects from the surfaces of the work

pieces. Optimum temperature for rol 1 ing depends upon

the composition of steel being used. For high carhons

it is J065-1100°C. For medium carhons the range is

1090-1145°C, an1l for low carbons it is about 1250°C.

The phenomenon of oxidation of steel surfaces

is known as scaling, and the oxides produced in hot

rolling process are known as mill seal e. The mechanism

of scale formation is regarded as of a dynamic nature,

with the highest oxides Fe 2o3 (haematite) being formed

first and then successively reduced by available iron

to Fe3o

4 (magnetite) and then to FeO.

Oxidation of the surface may also result into

decarbonisation of the surface layers because carbon

can easily migrate to the surface to form carbon

monoxide and carbon dioxide.

2.5 FERROMANGANESE ALLOY ITS FORMATION AND COHPOSITION

Ferromanganese is used in steel making as an

alloying material, and for deoxidising purposes. Based

on carbon content, ferromanganese has been divided into

two types ( 1 I High carbon ferromanganese, and ( 2)

Medium carbon ferromanganese. The percent composition

of high carbon ferromanganese is C 7 .5, Mn 70-74, Si

1.50, P 0.43, S 0.05, Fe-Balance. The medium carbon

ferromanganese has the following percent composition :

C 2.0, ~!n 70-75, Si 2.0, P 0.2, S 0.01, Fe-Balance.

Ferromanganese is a costly material.

The ferromanganese a 11 oy is proclucccl 1 n

electric arc ftlrnace. The raw materials

1111111111111mlllll T 12080

1 fJ..c9c

51

manganese ore, pig iron scrap, lime stone and dolomite.

These materials are melted, and the alloy and the slag

are tapped either separately or together in ladles. The

ferromanganese lumps are crushed and screened to

desired size,

2.6 METALLURGICAL MATERIALS AS ELECTROCHEMICAL REDUCTANTS : EXPLORATORY STUDIES

The types of the metallurgical materials having

been indentified , they were subjected to qualitative

tests to detect their capabilities to cause

electrochemical reduction. the tests were carried out

as follows :

(i) Reaction with silver nitrate solution

\-Jeighed quantities ( 10 g each) of the powdered

samples of the metallurgical materials (blast furnace

slag, foundry slag, zinc smelter slag, mill scales and

ferromanganese alloy) were placed in separate glass

vessels, and SO ml of silver nitrate solution (0.1 M)

was added to each, after which the mixtures were kept

for observation. A shiny deposition of metallic silver

was observed in each reaction mixture confirming that

the silver ions IE 0 = •0.799VI had undergone

electrochemical reduction in each case resulting in the

precipiration of silver metal (A!!-+ + e-+ Ag 0 ) .

52

( ii) Study of the re1 ative rates of the reduction reacactions of the metallurgical materials

For this purpose, weighed quantities (5 g each)

of the samples of the above stated metallurgical

materials were added to 250 ml of a silver nitrate

53

solution (O.OSM) in separate glass vessels. Aliquots (Sml ·

each) were drawn at known intervals and the

concentrations of Ag +

' FeZ+ and Mn 2+ ions were

determined in each aliquot. The silver ion

concentration was determined ti trimetrically using

standard solution (Siol as indicator (15). The ferrous

ion concentration was determined spectrophotometrically

using 1, 10 orthopenanthroline solution, measuring

absorbance at 515 nm (15), after the removal of

interference of Ag+ by precipitation as AgCl (15). The

manganese concentration was also determined

spectrophotometrical] y using KI04

as oxidant, and

measuring the absorbance at 545 nm after boiling in

HN03 solution (15).

The result obtained have been shown in Table

2-1. The relationships between variations in

concentrations of Ag(I), Fe(II) and Mn(Il) ions with

duration for each of the selected metallurgical

materials have been shown in Fig 2-2.

S.N

o.

1.

2 .

3.

4.

5 .

~1aterial s

~leta]

Th

eir

in

itia

l T

heir

co

ncen

trati

on

(m

g/1

) fo

un

d

aft

er

use

d

Ion

s co

ncen

trati

on

s (m

g/1

) 30

m

in

~

Ste

el

Pla

nt

Ag

(I)

53

.88

3

0.7

1

Gra

nu

late

d

Fe

(II)

N

IL

32

.00

sl

ag

M

n (I

I)

NIL

4

.10

Fo

un

dry

A

g C

I l

53

.88

3

2.6

7

Sla

g

Fe

(II)

N

IL

29

.00

M

n (I

I)

NIL

4

.00

Zin

c S

melt

er

Ag

(I)

53

.88

1

5.9

6

Sla

g

Fe

(II)

N

IL

51

.10

M

n (I

I)

NIL

1

.10

Mil

l S

cale

A

g(I

) 5

3.8

8

12

.21

F

e (I I)

NIL

9

7.0

0

Mn (I

I)

NIL

N

IL

Fer

rom

ang

anes

e A

g(I

) 5

3.8

8

11

.32

F

e( I

I)

NIL

4

2.0

0

Mn (I

I)

Nil

6

2.8

0

*M

ult

ipli

cati

on

fa

cto

r 1

03

for

all

A

g(I

) co

ncen

trati

on

s

60

min

90

m

in

28

.09

2

0.3

4

34

.00

4

0.0

0

4.2

0

4.

70

28

.52

2

8.0

3

29

.50

3

3.1

0

4.0

0

4.2

1

15

.28

1

2.9

0

55

.60

7

.40

1

.24

1

. 51

10

.01

6

.10

1

05

.00

1

12

.00

N

IL

NIL

10

.24

4

.30

4

3. o

o·

52

.00

6

4.6

0

70

.00

12

0

min

16

.52

4

3.0

0

4.7

0

22

.83

3

4.0

0

4.

30

12

.80

6

2.1

0

1. 5

3

2.5

0

11

5.0

0

NIL

Nil

6

1.0

0

79

.00

150

min

16

.52

4

3.0

0

4.

70

22

.42

2

5.0

0

4.5

0

12

.80

6

3.0

0

1.

60

NIL

1

15

.00

N

IL

NIL

6

1.0

0

79

.00

C1'l ~

1()­

c,olsrF:EL

' so '

I, 0·

30-

0

PL;\NT GFU\NUL/\lF:O SL/\G

--~ r·,,

0 Fe

·J JO GO 90 120 150

LJUn,.~TICf,) ( rninUtQS)

Fe

MILL SCALE

Mn

Fe

FERROMANG.<\NESE ALLOY

Ag

0 30 GO 90 120 150

DURATION ( mtnutes)

-2 7::c: '1,\Y:::c: 01 ELI'ClP'•rtrrc; !C/\L PF/ICTIOIJS IN I'RESEUCE OF DIFFi:RENT

·:.--.- ~:.L :.~,r\:rr?·,' !_:O.

55

56

2. 7. METALLURGICAL MATERIALS DETERMINATION OF

REDUCTION CAPACITIES

INTRODUCTION

The metallurgical material chosen for their

applications in the present work are Steel Plant (blast

furnace) slag (granulated), steel foundry slag, zinc

smelter slag, mill scales and ferromanganese alloy.

Before undertaking the study of their applications it

was considered helpful to eva 1 uate the relative

capacities of these metallurgical wastes for causing the

el ctrochemical reduction. The electrochemical reduction

capacity of a metallurgical material has been

arbitrarily taken here as the weight of silver ions in

milligrams precipitated by 1 g of the waste in particle

forms of 100 mesh size when allowed to remain in contact

with 10 ml of a O.lM AgN0 3 solution for a duration of

60 seconds at the room temperature. There may be some

imperfections in this arbitrary definition on account of

the probabi 1 ity of the rem ova 1 of silver ions by

processes other than electrochemical reduction such as

surface adsorption, ion-exchange, chemical precipitation

etc. However, the capacity as defined here has been

found to be of practical use and served the purpose of

the intended investigations to a reasonable extent.

MATERIALS AND METHODS

~~~rle Collection Samples ( 1 kg Cilchl of the

granul a red slag of a steel plant, and foundrv sl ar ~o.·crc•

57

collected from Bhilai Steel Plant and Himmat Steel Works

located at Bhilai and Kumhari (Distt.Durg) respectively.

The sample of zinc smelter slag 1 kg) was received

from the zinc smelter plant located at Chittorgarh

(Rajasthan). The samples of mill scale and

ferromanganese alloy 1 kg each) were obtained from

Bhil ai Steel Plant. The samples were powdered by a

grinding mill, and fractions of the powdered samples of

100 mesh size were obtained. In the case of

ferromanganese alloy, the samples were prepared by

drilling of the blocks followed by powdering in the

mill. Two more samples, one of iron filings and another

of aluminium foils were obtained from the local market,

and simi 1 a rl y processed. These samples corresponded to

two reactive metals in their elemental states, and have

been chosen here so that the reduction capacities of the

selected metallurgical wastes could be compared with

those of these reactive metals.

PROCEDURE

Reagent Solutions

Silver Nitrate Solution (0.1 M) : Prepared by dissol'ving

1.69R8 g AgN0 3 (BDH AnalaR make) in 100 ml distilled

water.

S0dium Chloride Solution (0.1 Ml p r er ilr cd hv

di!>solv!ng O.'i84'i g NaCl (1\Dil An<JlaR) in 100 ,.,]

distilled w<Jter.

58

Potassium Chromate Solution : Prepared by dissolving 5 g

Potassium Chromate (BDH AnalaR) in 100 ml distilled

water.

Accurately weighed quantities (1 g each) of the

powdered samples were taken in 100 ml beakers and mixed

with 10 ml of the silver nitrate solution. At the close

of 60 seconds the mixtures were decanted through

sintered crucible, and the silver ion concentrations

determined titrimetrically using NaCl and potassium

chromate solution as indicator (16). The decrease in the

concentration of silver ions was then found out by

calculation. The procedure was repeated in case of all

the seven samples used here. The electrochemical

reduction capacities of the samples thus found out have

been shown in Table 2-2 below.

Table 2-2 THE ELECTROCHEMICAL REDUCTION CAPACITIES OF

METALLURGICAL SAMPLES

Samples used

Iron filings

Aluminium foils

Electrochemical reduction capacities ( mg Ag/g of samples)

Blast furnace granulated slag

Foundry slag

23.6

14.9

4.1

4.0 11.6 Zinc Smelter slag

Hill scale

Ferromanganese alloy 20.2

2 2. 1

59

RESULTS AND DISCUSSION

In has been found that the most available and

economical waste material is the granulated slag

obtained from the blast furnaces of the steel plants.

This is followed by the foundry slags.The other

materials are in the following order of their

availabilities Zinc smelter slag > mill scale >

ferromanganese alloy. The last material, i.e., the

ferromanganese alloy is the most expensive, and its

inclusion here is to examine the response of a material

containing mostly iron and manganese.

The response of the selected materials towards

electrochemical reduction has been found positive when

each of the material exhibited a shiny deposition of

metallic silver on interaction with silver nitrate

solution. When the relative rates of reduction reactions

of the metallurgical materials were examined under

similar conditions, it was found that the ferromanganese

alloy and the mill seale exhibited the fastest rates

fall owed by zinc smelter slag, steel plant slag and the

foundry slag.

The products of electrochemical reactions· are

most] y Fe( II) and ~In( II) ions in the case of steel plant

slag, foundry slag, zinc smelter slag and ferromanganese

alloy. The mill scale did not exhibit any release of

manganese ions due to the absence of this el C'r.cnt i 11 it.

60

The zinc smelter slag is susceptible to release Zn(II)

and Pb(III ions also in view of the significant presence

of these in the slag. (The formation of Zn II, and Pb II

ions was not studied, hence their values not shown in

the data table). By taking the total quantities of the

reaction products into account, the reaction rates of

the materials were found to be in the following order :

ferromanganese > mill scale > zinc smelter slag > steel

plant slag > foundry slag. This sequence is almost the

same as found and reported above. When the reduction

capacities of the metallurgical materials were examined,

the same were found in the following order

ferromanganese alloy > mill scale > zinc smelter slag >

steel plant slag > foundry slag. The reduction

capacities of iron filings and aluminium foils as pure

metallic materials were also examined. While the

reduction capacity of iron filings was found close to

that of ferromanganese, that of aluminium foil was found

to be 1 ow.

Taking into view the overall aspects of economy,

availability, reaction rates and the reduction

capacities, the granulated slag of the steel plant was

found t9'be the most suitable material, although it was

found superior to only the foundry slag and Jess

effective than the ferromanganese al 1 oy, mil 1 seale and

the zinc smelter slag. Therefore, for making the methncls

cost effective

applications, the

preferred.

and

use

expanding

of steel

the scope

plant slag

of

has

their

he en

61

SUMMARY

This chapter is devoted mostly to the

exploratory work. The metallurgical materials such as

steel plant slag, foundry slag, zinc smelter slag, mill

scale and ferromanganese alloy were indentified here as

the source materials for causing the electrochemical

reduct ion of toxic species, the details of which are

being given in subsequent chapters. The details with

regard to the genesis, availabilities, compositions and

the reduction behaviours of the materials have been

collected through the literature survey, and also

investigated experimentally where necessary. The steel

plant slag was found to be the most available and

economical waste material for the proposed studies. This

is followed by foundr~slag, zinc smelter slag, mill

scales and ferromanganese alloy. The last named material

was found to

mostly for

principles.

demonstrate

indications

reactions.

be expensive, and its

the

All

verification of

these materials

qualitative as well

inclusion here was

the underlying

were found to

as quantitative

of causing electrochemical reduction

The relative rates of reductions of these

materials lvere studied, and the same were found in the

follmving order ferromanganese alloy > mi 11 seale >

zinc smelter slag>steel plant slag > foundry slag. The

reduction caracities, in terms of weight of silver ions

reduced per gram of material used, were experimentally

determined, and the same were found to be in the

following order ferromanganese alloy > mill scale >

zinc smelter slag> steel plant slag> foundry slag.

Taking into account the overall aspects of

economy, ·availability, reaction rates and the reduction

capacities, "' the g~,nulated slag of steel plant was found

to be the most suitable material, although it was found

superior to only the foundry slag and less effective

than the ferromanganese alloy, mill scale and the zinc

smelter slag.

62

63

REFERENCES

1. US Steel Publn., "Making, Shaping and Treating of Steel" United States Steel, (7th edn.) ( 1957) 174-75.

2. Tupkary, R.H.,"Introduction to Modern Iron Making" Khanna Publishers, Delhi (1982) 128-129.

3. Gromov,B.V.,"Utilization of Metallurgical Slags in the Soviet Union", Industry and Environment, 7 (2) (1984) 12-13.

4. Singh,Narinder, Shrivastava,K.N.,Krishnan,R.M., Nijhavan,B.R.,"Scope for Utilization of Slags and Related \~astes from Indian Iron and Steel Plants", Symposium on Utilization of Metallurgical Wastes, Jamshedpur (March 10-18,1964) 192-195.

5. BSP Publn.,"Horks Visit Notes -- An Orientation Guide'', Training and Management Department, Bhilai Steel Plant, Bhilai (1986) 54.

6. Chopra,S.K. ,Taneja,C.A. ,"Utilization of the Indian Blast Furnace Slags", Symposium on Utilization of Metallurgical \~astes, Jamshedpur, (March 10-18, 1964) 224,225.

7. Bhinde ,A.D. ,Sundarsan,B.B., "Solid-Waste Management in Developing Countries",INSDOC, New Delhi (1983) 30.

8. Anonymous,"\~orld Steel in figures-1992", Iron and Steel Engineer, 69, 10 (1992),47-48.

9. Sangameshwaran,K.R.,"Coke Furnaces", Transactions of ~!etals, 31 ( 2) ( 1978) 121.

Economy in Blast the Indian Institute of

10. "The new Caxton Encyclopedia",Vol.VI,Thames Publishing Corporation, London, ( 1969).

11. "The New Book of Knowledge", Vol.II, Gralier Incorporated, New York, (1973).

12. CEI Pub ln., "Handbook of Statistics", Confederation of Engineering Industries, New Delhi (1987).

13. Hoitra,J.K. and Pandey,G.S. ,"Steel Foundry Wastes: Study of Pollutants of Slags and Effluents", ~dian Journal of Environ.Protecs 9 (5) (1CJR9).

14. ~!ukherjce,A.D.! Pre.mkumar,G. and Dhana Sckaran,R., Pnmary Lead Smel tlng at HZL, Hind Zinc Tech 3 No.I, (19<J1). --' '

15. Bassett ,J., Denny ,C. H. and Mendham ,J., Vogel's Quantitative Inorganic Analysis (4th Language Book Society/Longman,Essex, (1986).

Textbook of edn), English

64